On Fri, Dec 24, 2010 at 7:13 AM, Steve Faulkner
<faulkner.steve@gmail.com> wrote:
> The ARIA spec does not prohibit the use of any roles on structural
> elements such as headings, but it is
> unequivocal about role=presentation in this case:
>
> "If an element with a role of presentation is focusable, user agents
> MUST ignore the normal effect of the role and expose the element with
> implicit native semantics, in order to ensure that the element is both
> understandable and operable."
Hmm … thinking about it, that provision is rather dangerous.
In some UAs it would lead to role="presentation" being ignored on
structural elements because they allow the structural elements to
receive some sort of focus.
Opera Mini 3 introduced "content folding".
http://www.opera.com/press/releases/2006/11/28/http://www.youtube.com/watch?v=lzTlmedXAlo
To reduce the amount of scrolling, it rolled up long lists of links
and provided a focusable button with a plus symbol for unrolling them.
For example:
<ul>
<li><a href="foo">Foo</a></li>
<li>Bar</li>
<li>Baz</li>
</ul>
Would be rolled up into a presentation like:
Foo [+]
Move focus to the [+] and activate it, and you get:
Foo
Bar
Baz
UC Browser provides a similar feature in it's adaptive view:
http://www.ucweb.com/English/UCbrowser/OperatingSkills.html#4
UAs are free to build focusable UIs on top of structural elements and
will then be required to ignore role="presentation".
This means authors cannot rely on role="presentation" being applied.
For interoperability, we should arguably discourage them using it.
Perhaps role="presentation" should be restricted to the "table"
element, as this is the element most widely abused for its
presentational qualities? This doesn't absolutely solve the problem
(in that UAs might build focusable UIs on top of table semantics, e.g.
allow column headers to be focused for native sorting) but at least
restricts it to one element.
ARIA could try to mandate that UAs apply formatting and ignore
semantics for all elements with role="presentation". Defining
"formatting" here could be problematic though.
--
Benjamin Hawkes-Lewis